Navigation systems accurately determine a user's present position using global positioning system data. The present position is then displayed to the user on a geocoded map. Mapping data may include topographical and road network information. Such information is typically communicated to the navigation system from a remote geospatial database or accessed from an onboard memory location. From the present position or from another starting point, the navigation system may automatically generate turn-by-turn driving directions to a desired destination. A recommended route is ultimately displayed in the form of a graphical route trace and/or as text- or speech-based driving directions.
Using geospatial data, the navigation system can provide precise driving directions to any location contained in the referenced geospatial database. The driving directions may be tailored to a user's preferences, for example a recommended travel route having the shortest overall distance, or a route which requires the least amount of travel time. Hybrid, battery electric, or extended-range electric vehicle designs that can be propelled using an electric traction motor, and thus with low or zero tailpipe emissions, may also display a route which minimizes the consumption of fossil fuel relative to other routes. Such a route is sometimes referred to as an eco-route.